Crude oil produced from production wells often contains waxy components that “freeze” to form wax crystals that can adhere to the pipe or conduit and subsequently block the pipe. The wax present in crude oils primarily consists of paraffin hydrocarbons (C18-C36) known as paraffin wax and naphthenic hydrocarbons (C30-C60).
When the temperature of the crude oil is lowered, which occurs when the oil is produced from a well deep under the surface of the ocean, crystals of wax begin to form on the walls of the pipe. Wax crystals can then continue to grow in size until the whole inner wall is covered. The partial blockage of the pipe requires additional pressure to move the hydrocarbons through the pipe and could eventually result in complete blockage of the pipe.